<%@ page import="java.util.List" %>
<%@ page import="java.util.ArrayList" %>
<%@ page import="java.sql.Connection" %>
<%@ page import="java.sql.Statement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="java.sql.DriverManager" %><%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2018-4-3
  Time: 15:54
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>用户列表</title>
</head>
<body>

<style type="text/css">

    table {
        border-collapse: collapse;
    }

    td {
        border: 1px solid #000;
        padding: 10px;
    }
</style>

<h1>用户列表</h1>
<table>
    <tr>
        <td>编号</td>
        <td>用户名</td>
        <td>密码</td>
    </tr>

    <%
        class User{
            int id;
            String username;
            String password;
        }



        List<User> userList = new ArrayList<User>();

        // 从数据库中读取数据，并且放在userList中
        // 3 + 1
        // 以前的问题是什么？为什么要使用新的技术？为什么要使用xx技术？

        Connection connection = null;
        Statement statement = null;
        ResultSet resultSet = null;

        String sql = "select * from t_users";

        Class.forName("com.mysql.jdbc.Driver");

        connection = DriverManager.getConnection(
                "jdbc:mysql://172.16.10.50:3306/sctu_javaweb_2018?serverTimezone=UTC",
                "root",
                "123456"
        );

        statement = connection.createStatement();

        resultSet = statement.executeQuery(sql);

        // resultSet -> List
        while(resultSet.next()){
            int id = resultSet.getInt(1);
            String username = resultSet.getString(2);
            String password = resultSet.getString(3);

            // 面向对象三个特征：封装、继承、多态
            User user = new User();
            user.id = id;
            user.username = username;
            user.password = password;

            userList.add(user);

        }

        resultSet.close();
        statement.close();
        connection.close();



//        User chen = new User();
//        chen.id = 1;
//        chen.username = "chengongsuo";
//        chen.password = "abc";
//        userList.add(chen);
//
//        User john = new User();
//        john.id = 2;
//        john.username = "John";
//        john.password = "abcdefg";
//        userList.add(john);

        for (User user : userList){
            // 221 替换原则
            out.write("<tr><td>"+user.id+"</td><td>"
                    +user.username+"</td><td>"
                    +user.password+"</td></tr>");
        }
    %>


    <%--<tr>--%>
    <%--<td>2</td>--%>
    <%--<td>zhen</td>--%>
    <%--<td>123456</td>--%>
    <%--</tr>--%>
</table>

</body>
</html>